1. Field of the Invention
The present invention relates to a magnetic recording medium. More particularly, it relates to a magnetic recording medium with improved abrasion resistance to be used as an audio tape, a video tape, a magnetic disc, a magnetic drum and the like.
2. Description of the Prior Arts
Recently, in order to improve electromagnetic characteristics of a magnetic recording medium, particularly a video tape, attempts have been made to decrease sliding noise caused by a ferrite head by imparting an adequate abrasion property to the magnetic recording medium. For example, U.S. Pat. No. 4,460,651 discloses particulate alumina as an effective abrasive material.
In order to reduce noise due to particles contained in a magnetic layer, a particle size of magnetic powder has been reduced in addition to well dispersing the magnetic powder in the magnetic layer. Recently, the magnetic powder has a BET specific surface area of about 60 m.sup.2 /g. With the great decrease of the particle size of the magnetic powder, the magnetic recording medium loses its abrasion property, this resuting in increase of sliding noise. In case of the magnetic recording medium, particularly the video type containing extremely fine magnetic powder, although a conventional abrasive material can impart an abrasion property to the magnetic recording medium, the strength of the magnetic layer containing such magnetic powder is not necessarily sufficient and its abrasion resistance is unsatisfactory.